How to Choose Sunscreen

What is Sunburn?

No matter the season or the temperature, our sun is constantly pumping out loads of ultra violet rays that would like nothing more than to attack your skin.

Your body is naturally protected by the epidermis, the outermost layer of skin. The cells most exposed - the ones you can see and touch - are all dead. However, just beneath the surface, new cells are constantly being generated to replenish your skin, keeping it clean and safe. But when UV rays hit the skin, they penetrate deep enough to touch living cells, effectively killing them.

In response to the newly dead cells, the body's natural reaction is to increase blood flow to the affected areas, causing the skin to become warm and red. When cells become damaged they release a combination of chemicals that activate pain receptors, which is why your skin feels as sensitive as it looks.

Sunburn and Skin Cancer Risk Factors

Facing the outdoors can be extremely gratifying and healthy, but there are risks inherent to prolonged sun exposure and certain attributes, both physical and genetic, that add to your own personal chances for injury.

Sunburn: We all know that people with fairer skin tend to burn more easily. This is because fair-skinned people don't produce as much melanin—a chemical that pigments the skin and offers some protection against sunburn (but not against skin cell damage!)—as darker-skinned people. There are six different skin types based on the amount of melanin produced, and each type has a different reaction to sun exposure:

In addition to skin type, living or traveling in sunnier climates and being at higher altitudes increases your chance of getting sunburned.

Skin Cancer: Skin cancer is sadly less avoidable and more severe, in most cases, than a sunburn. Here are a few risk factors for skin cancer outlined by the Centers for Disease Control and Prevention you should consider when determining how long you'd like to stay in the sun and what kind of protection you'd like to wear:

Naturally lighter skinFamily or personal history of skin cancerYour overall sun exposureHistory of sunburns, especially early in lifeHistory of indoor tanningBlue or green eyesBlonde or red hair

UV Rays

There are three types of UR rays: UVA, UVB and UVC. Both UVA and UVB are dangerous to your skin while UVC rays are blocked by our planet's ozone layer and are incapable of reaching Earth's surface.

UVA: The most common form of UV radiation, UVA rays are consistently attacking the skin year-round, penetrating deep in your skin and contributing to burning, premature aging of the skin and certain forms of skin cancer.UVB: UVB radiation is more harmful that it's siblings, reigning as the primary cause of burning, premature aging of the skin and the development of skin cancer.

How Sunscreen Works

When sunscreen was first created during World War II to help soldiers battle the burning Pacific sun, it was red and sticky with a consistency like jelly. Its creator, a pharmacist from Miami, developed the paste in his home using a veterinary petroleum-based compound. Overall, the product provided modest results, but after years of fine-tuning recipes, researchers have created astonishingly effective sunscreen.

Modern skin protection is typically derived from two varieties of ingredients:

Chemical: Using a variety of active chemical agents, these sunscreens work to absorb UV rays. They're odorless, colorless with a smooth and thin texture that manages to maintain its consistency as the sun protection factor, more commonly known as SPF, increases. Chemical sunscreens have become incredibly popular on account of their low cost, but their ingredients are known to cause irritation in sensitive skin.Mineral: Mineral sunscreens, also known as physical, are commonly composed of titanium dioxide and zinc oxide and, unlike their chemical counterpart, actively block UV rays from touching the skin. Mineral sunscreens are often touted as the safer of the two options, with their ingredients placing the wearer at a lower risk for skin irritation. The FDA provides blanketed approval for all physical sunscreens, generally recognizing them as safe. However, some chemical sunscreens are still considered dangerous to your skin.Still, there are disadvantages to mineral sunscreens, as well. While in lower SPF ranges they match chemical options in terms of overall protection, but as coverage increases, they become less and less effective against UVA rays.

What is SPF?

All modern sunscreens are accompanied by an SPF rating, which allows customers to see how effective the product will be.

An interesting way to look at SPF is to determine how long you can stay in the sun with any given rating before you start to burn. The equation goes like this: duration of time before burning multiplied by the SPF rating equals how long you can spend in the sun before burning. Let's say you start to burn after 10 minutes of hanging out in the sun. Sunscreen with a rating of SPF 15 would give you 150 minutes of sun time before your skin's in trouble.

The best sunscreens for active outdoor sports range between SPF 20 and 30. These levels have slightly fewer UV-reflecting ingredients, allowing your skin to breathe and sweat more easily. If you know you'll be at high elevations and don't suspect you'll be too active, you may want to opt for SPF 50. While this may weigh heavily on your skin and affect its breathability, it's certainly the best protection against sunburn. SPF 45 or 50 is also ideal for protecting children and toddlers, who have less-durable skin. This goes for thinner skin on you, too, such as the nose and ears.

Keep in mind, though, that when SPF ratings are determined, laboratory testing often uses much more sunscreen than we typically lather on. True numbers suggests outdoor enthusiasts use only about half the amount scientists use to determine SPF ratings. So really, you'll need to throw on twice as much as usual for base protection.

Sweat- and Water-Resistance

The science behind sunscreen has come a long way since its red, sticky predecessor. However, protection is still limited and temporary. Like most other creams or pastes that are applied directly to the skin, if sunscreen is assaulted with water and sweat eventually it will wear off and/or lose its effectiveness.

Many products will throw on grand labels claiming to be waterproof or sweat proof, but the reality is they're only resistant. According to new Food and Drug Administration guidelines, sunscreens can only market themselves as water or sweat resistant if they're capable of maintaining their SPF after 40 minutes of immersion. Some higher-end sunscreens are able to stay effective even after 80 minutes in the water.

It's important to remember that simple things like drying yourself off with a towel can also diminish the effectiveness of sunscreens.

Which is Best?

Sunscreens typically come in either cream, gel or spray form and provide SPF ratings ranging from 15 to 100. Although, the higher numbers are a bit misleading. Personal preference will play a large role in determining which product you actually choose to buy, but there are a few physical factors to consider:

Children: With soft, sensitive skin, babies and young children should avoid using chemical-based sunscreens that might cause irritation. Parents would be smart to try one of the several spray bottles or tubes decoratively designed to be more kid friendly, because, to be honest, getting children used to sunscreen is half the battle.Seniors: In our old age we have already absorbed large amounts of UV radiation throughout our lifetime, but it's still necessary to keep skin protected when outside to avoid age spots and skin cancer. Decreased mobility make spray sunscreens are optimal choice for seniors who'll appreciate the ease of application.Allergy- or Acne-Prone Skin: Much like children, who also have sensitive skin, mineral sunscreens work best if you regularly suffer from allergies or acne. For allergies specifically, make sure to also avoid sunscreens that contain alcohol, as they're liable to dry out your skin. Person with acne, however, would benefit from many of the gel products that include alcohol, which are less likely to aggravate the condition, but should stay away from greasy creams.Dry Skin: Many sunscreens include moisturizing agents such as lanolin, oils and silicones. Coming generally in the form of creams, lotions and ointments, hydrating products are great for keeping your skin safe and healthy.Fair Skin or a History of Cancer: As alluded to earlier, people rarely wear the amount of sunscreen necessary to achieve the SPF listed on the bottle. That is why if you have particularly fair skin or a history of cancer in your family you should always try to wear a sunscreen of at least SPF 30 for the extra protection.Dark Skin Tones: It's a common misconception that people with darker skin who aren't prone to tanning or burning don't really need sunscreen. The truth of the matter is that UV radiation is still harmful, though less so. Chemical sunscreens with an SPF of at least 15 are usually preferred as mineral products tend to be thick and remain chalky and white against dark skin.

Other tips

If you can find it, always spring for sunscreen that boasts both UVA and UVB protection. Sunscreen provides ample protection from the sun when it's first applied, but after about two hours its effectiveness has usually diminished greatly. Regular reapplication is necessary to extend your protection.Sunscreen typically takes as much as 30 minutes to absorb into the skin, so apply it before you go outside.Don't be shy about going heavy with the lotion. Sunscreen is meant to be applied liberally to every part of exposed skin, including your ears and feet.